/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.channel.udt.nio;

import com.barchart.udt.TypeUDT;
import com.barchart.udt.nio.SocketChannelUDT;
import io.netty.buffer.ByteBuf;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.util.internal.SocketUtils;
import io.netty.channel.nio.AbstractNioMessageChannel;
import io.netty.channel.udt.DefaultUdtChannelConfig;
import io.netty.channel.udt.UdtChannel;
import io.netty.channel.udt.UdtChannelConfig;
import io.netty.channel.udt.UdtMessage;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;

import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.List;

import static java.nio.channels.SelectionKey.*;

/**
 * Message Connector for UDT Datagrams.
 * <p>
 * Note: send/receive must use {@link UdtMessage} in the pipeline
 *
 * @deprecated The UDT transport is no longer maintained and will be removed.
 */
@Deprecated
public class NioUdtMessageConnectorChannel extends AbstractNioMessageChannel
        implements UdtChannel
{

    private static final InternalLogger logger = InternalLoggerFactory
            .getInstance(NioUdtMessageConnectorChannel.class);

    private static final ChannelMetadata METADATA = new ChannelMetadata(false);

    private final UdtChannelConfig config;

    public NioUdtMessageConnectorChannel()
    {
        this(TypeUDT.DATAGRAM);
    }

    public NioUdtMessageConnectorChannel(final Channel parent,
            final SocketChannelUDT channelUDT)
    {
        super(parent, channelUDT, OP_READ);
        try
        {
            channelUDT.configureBlocking(false);
            switch (channelUDT.socketUDT().status())
            {
                case INIT:
                case OPENED:
                    config = new DefaultUdtChannelConfig(this, channelUDT,
                            true);
                    break;
                default:
                    config = new DefaultUdtChannelConfig(this, channelUDT,
                            false);
                    break;
            }
        }
        catch (final Exception e)
        {
            try
            {
                channelUDT.close();
            }
            catch (final Exception e2)
            {
                if (logger.isWarnEnabled())
                {
                    logger.warn("Failed to close channel.", e2);
                }
            }
            throw new ChannelException("Failed to configure channel.", e);
        }
    }

    public NioUdtMessageConnectorChannel(final SocketChannelUDT channelUDT)
    {
        this(null, channelUDT);
    }

    public NioUdtMessageConnectorChannel(final TypeUDT type)
    {
        this(NioUdtProvider.newConnectorChannelUDT(type));
    }

    @Override
    public UdtChannelConfig config()
    {
        return config;
    }

    @Override
    protected void doBind(final SocketAddress localAddress) throws Exception
    {
        SocketUtils.bind(javaChannel(), localAddress);
    }

    @Override
    protected void doClose() throws Exception
    {
        javaChannel().close();
    }

    @Override
    protected boolean doConnect(final SocketAddress remoteAddress,
            final SocketAddress localAddress) throws Exception
    {
        doBind(localAddress != null ? localAddress : new InetSocketAddress(0));
        boolean success = false;
        try
        {
            final boolean connected = SocketUtils.connect(javaChannel(),
                    remoteAddress);
            if (!connected)
            {
                selectionKey()
                        .interestOps(selectionKey().interestOps() | OP_CONNECT);
            }
            success = true;
            return connected;
        }
        finally
        {
            if (!success)
            {
                doClose();
            }
        }
    }

    @Override
    protected void doDisconnect() throws Exception
    {
        doClose();
    }

    @Override
    protected void doFinishConnect() throws Exception
    {
        if (javaChannel().finishConnect())
        {
            selectionKey()
                    .interestOps(selectionKey().interestOps() & ~OP_CONNECT);
        }
        else
        {
            throw new Error(
                    "Provider error: failed to finish connect. Provider library should be upgraded.");
        }
    }

    @Override
    protected int doReadMessages(List<Object> buf) throws Exception
    {

        final int maximumMessageSize = config.getReceiveBufferSize();

        final ByteBuf byteBuf = config.getAllocator()
                .directBuffer(maximumMessageSize);

        final int receivedMessageSize = byteBuf.writeBytes(javaChannel(),
                maximumMessageSize);

        if (receivedMessageSize <= 0)
        {
            byteBuf.release();
            return 0;
        }

        if (receivedMessageSize >= maximumMessageSize)
        {
            javaChannel().close();
            throw new ChannelException(
                    "Invalid config : increase receive buffer size to avoid message truncation");
        }

        // delivers a message
        buf.add(new UdtMessage(byteBuf));

        return 1;
    }

    @Override
    protected boolean doWriteMessage(Object msg, ChannelOutboundBuffer in)
            throws Exception
    {
        // expects a message
        final UdtMessage message = (UdtMessage) msg;

        final ByteBuf byteBuf = message.content();

        final int messageSize = byteBuf.readableBytes();
        if (messageSize == 0)
        {
            return true;
        }

        final long writtenBytes;
        if (byteBuf.nioBufferCount() == 1)
        {
            writtenBytes = javaChannel().write(byteBuf.nioBuffer());
        }
        else
        {
            writtenBytes = javaChannel().write(byteBuf.nioBuffers());
        }

        // wrote message completely
        if (writtenBytes > 0 && writtenBytes != messageSize)
        {
            throw new Error(
                    "Provider error: failed to write message. Provider library should be upgraded.");
        }

        return writtenBytes > 0;
    }

    @Override
    public boolean isActive()
    {
        final SocketChannelUDT channelUDT = javaChannel();
        return channelUDT.isOpen() && channelUDT.isConnectFinished();
    }

    @Override
    protected SocketChannelUDT javaChannel()
    {
        return (SocketChannelUDT) super.javaChannel();
    }

    @Override
    protected SocketAddress localAddress0()
    {
        return javaChannel().socket().getLocalSocketAddress();
    }

    @Override
    public ChannelMetadata metadata()
    {
        return METADATA;
    }

    @Override
    protected SocketAddress remoteAddress0()
    {
        return javaChannel().socket().getRemoteSocketAddress();
    }

    @Override
    public InetSocketAddress localAddress()
    {
        return (InetSocketAddress) super.localAddress();
    }

    @Override
    public InetSocketAddress remoteAddress()
    {
        return (InetSocketAddress) super.remoteAddress();
    }
}
